Le 23/06/2021 à 11:46, Dan Carpenter a écrit :

On Wed, Jun 23, 2021 at 07:22:45AM +0200, Christophe JAILLET wrote:

...

If 'of_clk_add_hw_provider()' fails, the previous 'for' loop will have run completely and 'i' is know to be 'DA7219_DAI_NUM_CLKS'.

In such a case, there will be an out-of-bounds access when using 'da7219->dai_clks_lookup[i]' and '&da7219->dai_clks_hw[i]'.

To avoid that, add a new label, 'err_free_all', which set the expected value of 'i' in such a case.

Fixes: 78013a1cf297 ("ASoC: da7219: Fix clock handling around codec level probe") Signed-off-by: Christophe JAILLET christophe.jaillet@wanadoo.fr

---

sound/soc/codecs/da7219.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/sound/soc/codecs/da7219.c b/sound/soc/codecs/da7219.c index 13009d08b09a..1e8b491d1fd3 100644 --- a/sound/soc/codecs/da7219.c +++ b/sound/soc/codecs/da7219.c @@ -2204,12 +2204,14 @@ static int da7219_register_dai_clks(struct snd_soc_component *component) da7219->clk_hw_data); if (ret) { dev_err(dev, "Failed to register clock provider\n");

• 	goto err;
  

• 	goto err_free_all;
  

  } }

  return 0;

+err_free_all:

• i = DA7219_DAI_NUM_CLKS - 1; err: do { if (da7219->dai_clks_lookup[i])

This do while statement is wrong and it leads to potentially calling clk_hw_unregister() on clks that haven't been registered.

Obviously right.

Thanks for the review Dan. I'll send a v2 in the coming days.

CJ

I think that calling clk_hw_unregister() on unregistered clocks is supposed to okay but I found a case where it leads to a WARN_ON() (Nothing else harmful). It's in __clk_register() if the alloc_clk() fails:

hw->clk = alloc_clk(core, NULL, NULL); if (IS_ERR(hw->clk)) { ret = PTR_ERR(hw->clk); goto fail_create_clk; // <- forgot to set hw->clk = NULL }

The better way to handle errors from loops is to clean up partial iterations before doing the goto. So add a clk_hw_unregister() if the dai_clk_lookup = clkdev_hw_create() assignment fails. Then use a while (--i >= 0) loop in the unwind section:

err_free_all: i = DA7219_DAI_NUM_CLKS; err: while (--i >= 0) {

regards, dan carpenter